Money of course and with no real regulated testing to get their load rating, it's a panacea. Why does GM make both GM trucks and Chevy? To corner more of the market. Don't forget you posted a trailer tire salesman's take on things. Forget a salesman on youtube and do some real homework. Just start with his first lie and go from there. Take an uninflated unmounted ST tire and push down and test the strength of the sidewall he's touting. Then do the same on an LT. You'll be amazed. My towmax tires were like wet noodles compared to my Goodyear G614's. The proceed to the next lie... and the next...